This patent application is related in part to patents concerning estimation of the effective range of a communications system, including U.S. Pat. No. 8,184,036 B2, Canada patent 2,624,233, Australia patent 2008201111, and United Kingdom patent GB2449151, the contents of which are hereby incorporated by reference in their entireties.
There are certain communications devices whose normal operating mode involves passively monitoring the electromagnetic signal environment and classifying the various signals it detects. When certain signals are detected, the system may respond by any or all of following actions: 1) radiate a signal, 2) alert an operator or secondary system, and 3) recording the detected signal of interest.
An example of such a communications system is a so-called electronic countermeasures (ECM) system, also known as a jammer. ECM is a subset of electronic warfare (EW) in which signals are radiated with the intention to render a hostile weapon system ineffective; examples include ECM systems to counter missile systems, communications systems, surveillance and targeting radars, and radio controlled improvised explosive devices (RCIEDs). In many cases, the ECM system is intended to provide protection not just for the host platform, but for accompanying protectees such as other platforms, vehicles, equipment or people. In most cases, the effectiveness of the ECM is limited to a volume of space, and protectees must remain inside this space to benefit from the protection provided by the ECM. In the more general case of a communication system, agents that wish to benefit from the capabilities of the communication system must remain within its effective volume.